I see this mainly in running. When a person can simply stay healthy for a few months good race results usually follow. Stay healthy for a year, really good race results follow. The same applies to everything else too. Blog regularly, and I will become better at it. Engineer more (instead of being unemployed I suppose) and my engineering will be better.
People are often trying to hit one project or event out of the ballpark. Trying to go viral or have a big opening weekend. When it doesn't work after some length of time they move on to the next project. On the other hand, putting in the time and the effort weekly and daily for months, and years, dare I say decades, will hone the skills needed to hit one out of the ball park. Before that crunch-time seventh-game ninth-inning homer though, expect to get on base just barely a few times, strike out a few times, get walked, hit a fly ball to an out, and hit more foul balls than anyone wants too.
If consistency, working hard on the days you don't want to, was easy, everyone would do it.